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Remove From List

by PyrexKidd (Monk)
on Sep 09, 2010 at 19:46 UTC ( #859551=perlquestion: print w/replies, xml ) Need Help??
PyrexKidd has asked for the wisdom of the Perl Monks concerning the following question:

I am trying to write a program that removes an entry from one of three lists. The program appears to work except the new files conf_list_* are empty except for the entries deleted. What am I missing?

#!/usr/bin/perl use strict; use warnings; use File::Copy ("cp"); my $announce_off = "master_conf_list_announce_off"; my $announce_on = "master_conf_list_announce_on"; my $beep_on = "master_conf_list_beep_on"; my $date = &getDate; my (%announce_off, %announce_on, %beep_on); print "$date\n"; #create Backup files in the backup folder. just incase anything goes +wrong. cp ("./master_list/$announce_off", "./master_list/backup/$announce_off +" . $date); cp ("./master_list/$announce_on", "./master_list/backup/$announce_on" +. $date); cp ("./master_list/$beep_on", "./master_list/backup/$beep_on" . $date) +; #create a scratch pad cp ("./master_list/$announce_off", "./master_list/$announce_off\.bak") +; cp ("./master_list/$announce_on", "./master_list/$announce_on\.bak"); cp ("./master_list/$beep_on", "./master_list/$beep_on\.bak"); #delete original files unlink ("./master_list/$announce_off"); unlink ("./master_list/$announce_on"); unlink ("./master_list/$beep_on"); #open files for reading open my $ANNOUNCE_OFFFH, '<', "./master_list/$announce_off\.bak"; open my $ANNOUNCE_ONFH, '<', "./master_list/$announce_on\.bak"; open my $BEEP_ONFH, '<', "./master_list/$beep_on\.bak"; open my $DELETE_LISTFH, '<', "$ARGV[0]"; #open files for writing open my $ANNOUNCE_OFFNEW, '>>', "./master_list/$announce_off"; open my $ANNOUNCE_ONNEW, '>>', "./master_list/$announce_on"; open my $BEEP_ONNEW, '>>', "./master_list/$beep_on"; open my $DELETED_ITEMS, '>>', "./deleted_items.txt"; #slurp each file into hash foreach (<$ANNOUNCE_OFFFH>){ chomp($_); $announce_off{$_} = 1; } foreach(<$ANNOUNCE_ONFH>){ chomp($_); $announce_on{$_} =1; } foreach(<$BEEP_ONFH>){ chomp($_); $beep_on{$_} = 1; } #parse through the list to delete for items to delete #print in either the old location or a liste of deleted files foreach (<$DELETE_LISTFH>){ chomp($_); print { exists $announce_off{$_} ? $ANNOUNCE_OFFNEW : $DELETED_ITE +MS } $_ ."\n"; print { exists $announce_on{$_} ? $ANNOUNCE_ONNEW : $DELETED_ITEMS +} $_ ."\n"; print { exists $beep_on{$_} ? $BEEP_ONNEW : $DELETED_ITEMS } $_ . +"\n"; } close $ANNOUNCE_OFFNEW; close $ANNOUNCE_ONNEW; close $BEEP_ONNEW; close $DELETED_ITEMS; sub getDate(){ my @months = qw(Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec); my(@weekDays) = qw(Sun Mon Tue Wed Thu Fri Sat Sun); my($second, $minute, $hour, $dayOfMonth, $month, $yearOffset, $day +OfWeek, $dayOfYear, $daylightSavings) = localtime(); my($year) = 1900 + $yearOffset; my($theTime) = "\_$dayOfMonth\_$months[$month]\_$hour$minute"; return $theTime; }

Thanks for any assistance in advance.


ok, so I know I have it backwards. When I parse through my files I don't actually DELETE the item, I just choose which file to print it to. Since I am just testing if a key exists, and if it does, I am printing it to a file. So the reason I come up with empty files is that I never print anything to my files...

rookie mistake

So this leads me to my next question, how do I remove said entries from the hash? I'll check Google. Does any one have any suggestions on a better way to do this? I'd like any comments/constructive criticisms.

Replies are listed 'Best First'.
Re: Remove From List
by Krambambuli (Curate) on Sep 09, 2010 at 20:57 UTC
    Sorry... forget my (first) answer, I totally misread your question.

    Use Perl's "delete" function to delete from a hash.


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